Slip box for sand molds



y 1957 w. E. WALKER, JR 2,800,694

SLIP BOX FOR SAND HOLDS Filed Feb. 16, 1955 States This invention relates to a slip box for sand molds and the like for maintaining the several parts thereof in assembled relation prior to, during, and after the pouring of the molten metal.

It is common practice in the metal casting art to use sand molds or other molds having two or more parts. The individual parts are normally placed one on top of the other and have inclined walls thereon. When metal is poured into the mold, the pressure exerted thereby tends to force the walls of the mold outwardly, thereby damaging the mold and ruining the cast article. To prevent this, a slip box is used which is lowered over the superposed portions of the mold until it is in contacting relation with the sloping exterior walls thereby preventing collapse or damage to the mold when molten metal is poured.

Slip boxes generally comprise four side walls which are rigidly or non-rigidly connected together. This invention relates to the non-rigid type wherein the walls are loosely or non-rigidly connected together in some suitable manner so that the slip box can compensate for slight variances in the dimensions of various molds and so the slip box can be applied and removed hurriedly without crushing or damaging the sides of the mold. In the past, posi tive movement limiting means were required at each corner of the slip box, thereby requiring extra material and labor, and introducing assembly problems. Furthermore, movement limiting means at each corner present obstructions and irregularities behind which and on which molten metal can catch and freeze the movement of the wall.

One of the principal objects of the present invention is to provide a slip box construction which requires movement or twist limiting means at one corner only. Another object is to provide improved twist limiting means comprising a pin or bar of predetermined size and shape secured to one member and extending into an opening of predetermined size in an adjacent overlapping member. This arrangement makes it easy to regulate or govern the degree of flexibility. Another object is to provide a relatively simple adjustable slip box construction which is easy to manufacture and assemble. Another object is to provide twist limiting means which is relatively unafiected by molten metal which might accidentally spill thereon, and which is protectively positioned to reduce the likelihood that molten metal may fall thereon. Still another object is to provide a slip box with no projections on the inner surfaces of the sides thereof so that the sides can be laid flat for straightening purposes after said sides have become Warped in normal use.

These and other objects and advantages will become apparent hereinafter.

The present invention is embodied in an adjustable slip box requiring positive twist limiting means at only one corner thereof, said twist limiting means comprising means on one side member adapted to cooperate with an adjacent side member.

The invention also consists in the parts and in the 23%,694 Patented July 30, 1957 arrangements and combinations of parts hereinafter described and claimed. In the accompanying drawings which form part of this specification and wherein like numerals and symbols refer to like parts wherever they occur:

Fig. 1 is a top plan view of an entire slip box embodying the present invention,

Fig. 2 is an enlarged perspective view of the twist limiting means in assembled relation,

Fig. 3 is a side elevational view of the slip box showing the side member having the twist limiting pin thereon,

Fig. 4 is a-side elevational view of the side member having the cooperating hole therein, and

Fig. 5 is an enlarged perspective View of a modified form of the invention wherein a twist limiting means is secured to the overlapping side member.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a self-adjusting slip box B having two opposed relatively long side members 1 and 2 and two opposed relatively short side members 3 and 4. Each side member is provided with a connecting rod 5 secured thereto preferably on the outer surface thereof in some suitable fashion, such as by welding, and a hole 6 in the opposite end thereof for receiving the connecting rod 5 of an adjacent side member. Each connecting rod 5 may be provided with threads '7 at the end thereof for receiving a nut or head 8. Each side member 14 comprises a relative flat side plate 9 having a longitudinal flange 10 extend-ing outwardly and away from the mold, not shown. Each side member is provided with a sloping or tapered end edge 11 which is overlapped by an adjacent side member and a sloping opposite end edge 12.

One of the side members 1 is provided with twist limiting means in the form of a stop pin 13 suitably secured to said side member 1 by means of welding preferably in parallel relation to and below said connecting rod 5. The stop bar extends past the tapered end edge 11 of the side plate 9 of the side member 1 sufficiently far so that it extends into the opening 14 even when the opening 14 is positioned at its greatest distance away from the tapered end edge 11 of the side member 1. As best shown in Fig. 2, the opening 14 is positioned outwardly from the inner face of the overlapped member 9 so that there are no openings in the flat interior Walls which contact the mold. If desired, one of the side members 3 may be provided with a carrying handle 15. The stop pin 13 is preferably positioned below or beneath the connecting rod 5 to protect said pin 13 and opening 14 from any molten metal which might accidentally fall on the corner of the slip box.

So long as the twist limiting pin 13 is within the opening 14, the slip box B is maintained in loose but controlled rectangular shape. Should the distance between the overlapping side member 3 having the opening 14 therein and the overlapped side member 1 having the pin 13 thereon be so great as to allow the pin 13 to be disengaged from the opening 14, then the entire four side members might twist or skew into a difiicult hard-tomanage mass of parts, assuming that the distance D between the inner end of the head 8 and the edge 11 at the connecting rod 5 of all members is so great as to permit this objectionable twisting. However, without changing any of the distances D, all objectionable twisting is eliminated simply by having the twist limiting means 13 on one side member 1 cooperating with an opening 14 on the adjacent side member.

It has been found that the foregoing construction, which requires twist limiting means at only one corner thereof, has all of the practical advantages of slip boxes requiring twist limiting means at each of the four corners.

If desired, each of the connectingrods can be provided with threads 7 for adjustably receiving a nut 8 to provide for minor adjustments and to further limit the movement of the overlapping member with respect to the end edge of. the adjacent overlapped member. Without the twist limiting means, the four side members if looselyassembled will twist or screw into a geometrical but relatively useless mass of connected parts which becomes difficult to handle in operation. By providing twistlimiting means at one corner, all objectionable twisting is eliminated in the entire self-adjusting slip box, even though no positive twist limiting means are positioned at the other three. corners.

It is believed. that the foregoing is accomplished by limiting rotation of the overlapping member around the connecting rod of the overlapped member as shown by the arrow in Fig. 2. Thus, the side member 3 is limited in rotation within its own plane and is limited in its pivotal movement wthin the distance D shown in Fig. 3 as represented by the arrow therein. This results in controlled movement of the edge 11 of side member 3 with respect to the side member 2, thereby limiting the movement of side member 2 which in turn limits the movement of side member 4. If desired, the opening 14 can take the shape of a depression in side member 3 instead of a hole as shown in order to provide a cover for the free end of the pin 13 so that there will be no chance for molten metal to freeze the movement at the twist limiting means.

Fig. shows a modified form of the invention wherein an L-shaped twist limiting lug 15 is welded to the inner surface of the side member 3 or that surface which faces toward the mold, not shown, at a point outwardly of the overlapped member 1. The lug 15 is adapted to abut against the outer surface of the overlapped member 1. Thus, the rotation of the member 3 about the connecting rod 5 of the overlapped member 1 as shown by the arrow is limited and prevents collapse or objectionable skewing of the entirev slip box as hereinbefore explained. In all forms of the invention, twist limiting means is required only at one corner of the slip box, not at all four corners.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention. 7

. What I claimis:

1. In a slip box having a plurality of angularly positioned side walls wherein one end portion of each side wall overlaps the end of an adjacent side wall, said side walls being non-rigidly connected together, the improvement which comprises mounting twist limiting means on only one side wall adapted to cooperate with the adjacent side wall for limiting the twist of all side walls and preventing collapse of said slip box.

2. In a slip box having a plurality of angularly positioned non-rigidly connected side walls, twist limiting means on only one side wall adapted to cooperate with an opening in an adjacet side wall thereby preventing collapse of said slip box.

3. A slip box comprising a plurality of loosely connected side members each having a connecting rod at one end thereof and means at the opposite end thereof for receiving the connecting rod of the adjacent side member, a twist limting pin secured to one of said side members in parallel relation to the connecting rod thereon and extending beyond the end edge of said side member, and an opening in the overlapping side member for receiving said twist limiting pin.

4. A slip box comprising four side members non-rigidly joined together to form a closed polygon, each of said side members having a connecting rod extending beyond one end edge thereof and a hole at the opposite end thereof adapted to receive the connecting rod of the adjacent overlapped member, twist limiting means secured to the outer face of one of said side members below and parallel to said connecting rod of said side member and extending beyond the same end edge thereof, said overlapping side member having an opening therein positioned outwardly from the inner face of said overlapped side member and adapted to receive said twist limiting means for limiting the amount of twist of said overlapping member about said connecting rod.

5. A slip box comprising four side members nonrigidly joined together to form aclosed polygon, each of said side members having sloping end edges and a connecting rod extending beyond one sloping end edge thereof and a hole at the opposite end thereof adapted to receive the connecting rod of the adjacent overlapped member, twist limiting means secured to only one of said side members extending substantially parallel to and beyond the same sloping end edge thereof, said overlapping side member having an opening therein adapted to receive said twist limiting means for limiting the amount of twist of said overlapping member about said connecting rod.

References Cited in the file of this patent UNITED STATES PATENTS 2,050,778 Bester Aug. 11, 1936 2,473,140 Erlbacher June 14, 1949 2,477,483 Hershey July 26, 1949 

